Drill



J. J. BOUCHAL FIGJ INVEN TOR J. J. ROUGH/1L A T TOPNEY Patented Oct. 19, 1943 DRILL Jerry J. Bouchal, Westfield, N. 1., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application November 7, 1941, Serial No. 418,137

-4 Claims. (01.145-116) This invention relates to drills, and more particularly to wood drills of the'power driven types handling as well as in service to avoid dulling the spurs and other cutting edges. For example, when drills of this type are used with drill fixtures they must be accurately aligned with the bushings of the drill fixture, otherwise the spurs striking the bushings will be dulled, requiring a special sharpening process that could not be performed on the conventional bench grinder.

An object of theinvention is to provide a drill of the woodworking type which is simple in structure, not easily dulled, self-aligned in use with a drill fixture, and easily sharpened.

With this and other objects in view, the invention comprises a drill of the woodworking type having a body with a spiral portion the forward end of which is bevelled, providing inwardly tapered cutting edges with companion cutting edges extending angularly inwardly to a center point, the cutting edges all having following relief portions of definite dimensions.

Other objects and advantages will be apparent from the following detailed description when taken in conjunction with the accompanying drawing, wherein I Fig. 1 is an elevational view of the drill;

Fig. 2 is an enlarged fragmentary view illustrating the contoursadjacent the cutting end and their relationship with respect to a bushing of a drill fixture;

Fig. 3 is an enlarged end elevational view of the drill, and

Fig. 4 is a fragmentary detailed view taken substantially along the line 4-4 of Fig. 3.

Referring now to the drawing, attention is first directed to Fig. 1, which illustrates the drill having a body Hi, the upper end of which is circular in cross section, as indicated at H, to bereceived in a chuck ofa drill press of any suitable type. The remainder of the body III in general is of spiral formation, as indicated at I 2.

Attention is now directed to Figs. 2 and 3,

. which illustrate a center point I, outer cutting edges [5 and inner cutting edges Hi. The outer cutting edges l5 and their relief portions I1 extend inwardly towardan extended center line of the drill, providing a bevelled end for the drill which serves as a guide for thealignment of the drill with a bushing l8 of adrill fixture IS. The bushing of the drill fixture has been selected for the purpose of illustration but it'should be under-- stood that the bevelled end will guide the drill into any selected apertured object or fixture. The relief portions l'l although arcuate in contour, extend inwardly a slight distance,-preferably seven degrees (Fig. 4), from their respective cutting edges 15, maintaining their bevelled formation yet relieving the cutting edges to assure accurate cutting of the drill into work 2| without splintering or chipping the work. To further assist in the aligning of the drill with the, bushing l8, each side of the spiral structure I2 is cut back as at 20, the surfaces of the portions 20 lying at like angles from the center line of the drill, these angles being preferably approximately eighteen degrees as indicated in 4, these cutaway portions also positioned in planes with adjacent surfaces of the center point I4, as illustrated in Fig. 4. The portions 20 are the following portions of the spiral portions, the cutting edges. I 5 extending from the leading portions thereof. Furthermore, due to,the angular relationship of the portions 20 withthe center line of the drill, they will assist the relief portions l1 in aligning the drill with the bushing l8. Although theportions 20 will engage the bushing after the latter is engaged by the portion l'l,

both sets of portions function in aligning the drill with the bushing.

The cutting edges i 6 are arcuate in contour, observing the end view of Fig. 3, to create a shearing effect on the work when the drill is in use. The cutting edges It; also extend inwardly toward the base of the point 14 at angles greater than right angles with respect to the center line of the drill and at angles greater than right angles with respect to the cutting edges 15. This relationship of the cutting edges also assures what might be termed cleaned cuts in the work, eliminating splintering or chipping of .the work and eliminating the leaving of a button on the end of the drill when the drill has completed the hole in the work. Each cutting edge I6 has a relief portion 22, extending inwardly at likeangles, preferably at angles approximately 'seven degrees, from a plane at right angles to the center line of the drill.

As previously described, the drill is of the woodworking type, meaning that it may be used for drilling holes in materials other than metal or similar structures. Although the drill is particularly designed for woodworking it is apparent that the drill could be used for other fibrous materials or plastics. Furthermore, although the drill was particularly adapted for use with drill presses it drills. which are easily dulled if brought in contact with could be readily used with hand drillsif'de sired.

The important advantages of the structure of" the drill are, first, that the drill with th relatively positioned cutting edges II and II will accurately cut into work without splintering or flaking the material of the work and without leaving the commonly known buttons on the end of the drill. .The contour of the point i4 facilitates in this last named advantage, the tapered edges of the point providing no holding means viding smooth tapered surfaces so that the button may freely drop therefrom. Second, each cutting edge is provided with accurate relief surfaces. Third, the relief surfaces i1 form a tapered end for the drill, serving to guide the drill into the drill bushing if there should not be accurate alignment thereof. Fourth, the conventional spurs common on wood drills hav been eliminated, using in their stead the cooperation of the cutting edges i and IS the vertices ofwhich serve with the point ll in directing the drill in a straight line through the work and assuring the cutting of a hole of the exact diame- "for the remaining material or button but pro- Asa cial grinding apparatus necessary for spur type Sixth, with the elimination of the spurs,

the drill bushing, and with the provision of the bevelled surfaces serving to eliminate dulling of the drill and aiding in the aligning of the drill with the bushing, the drill is assured of longer life between sharpening processes than the drill of the spur type. Seventh, the angles and contours of the cutting edges l5 and i6 bringabout a shearing of the material rather than a straight cut, resulting in a cleaner hole free of splintered orachipped portions. The contour of the cutting edges IS in Fig. 3 is illustrated and has previously been described as arcuate, obviously forming a shearing cut in the work. The cutting edges l5 of this figure are also illustrated as extending at angles so that a shearing action on the work will be created. Eighth, the contours of the cutawayportions 20 cooperate with the adjacent surfaces of the point it cooperating with the bevelled portions, namely the relief portions H, in aligning the drill with its bushing.

The embodiment of the invention herein disclosed is merely illustrative and may be widely modified and departed from in many ways withassasos out departing from th spirit and scope of the invention as pointed out in and limited solely by the appended claims.

What isclaimed is: V

1. A drill comprising a body having a mounting end and a cutting end with an intermediate spiral portion extending to the cutting end and having leading edges and following edges, cutting edges extending at like angles from the leading edges of the spiral portion in a direction away from the mounting end and toward the center of the body, a center point disposed at the center line of the body and having converging flat surfaces lying in different planes, and tapered surfaces formed at the following edges and lying respectively in certain of the said planes.

2. A drill comprising a body having a mounting end and a cutting end with an intermediate spiral portion extending to the cutting end and having leading edges and following edges, a center point disposed at the center line of the body and having converging flat surfaces lying in different planes, pairs of cutting edges, one extending at like angles from the leading edges and away from the mounting end, and the other extending at like angles from the inner extremities of the first pair toward th mounting end and to the base of the center point, and tapered sur faces formed .at the following edges and lying respectively in certain of the said planes.

3. A drill comprising a, body having a mounting end and a cutting end with an intermediate spiral portion extending to the cutting end and having leading edges and following edges, cutting edges extending at like angles from the lead ing edges of the spiral portion, a center point disposed at the center line of the body and having converging flat surfaces lying in planes approximately 18 from the center line, and tapered surfaces formed at the following edges and lying respectively in certain of the said planes.

4. A drill comprising a body having a mounting end and acutting end with an intermediate spiral portion extending to the cutting end and having leading edges and following edges, a center point disposed at the center line of the body and having outwardly converging flat surfaces lying in different planes, pairs of cutting edges, one extending at like angles from the leading edges and away from the mounting end, and the other extending at like angles from the inner extremities of the first pair toward the mounting end and to the base of the center point, ta-

pered surfaces formed at the following edges and lying respectively in the planes of an opposed pair of said flat surfaces, and bevelled relief surfaces for the first mentioned pair of cutting edges extending at similar angles from the periphery of the spiral portion.

JERRY J. BOUCHAL. 

